People seem to ignore the fact that with MCP you can serve up the tools the user wants and has access to instead of a rest api doc specifying every endpoint and bloating the context.
All those tools still get into context. Also, it's not hard to filter a rest api doc - like with a special tool for that the harness itself could pre-filter it and add only the relevant ones as tools to be even more leaner than what an MCP returns.
100% up to the harness. Most harnesses either fixed (or dymanically depending on size) nowadays add a "search_tool" tool to prevent spamming the context with all tools.
